1961-2010年环渤海地区寒潮时空分布及变化特征

利用1961-2010年环渤海地区58个站的逐日平均气温、日最低气温资料，按照寒潮国家标准统计寒潮次数和寒潮强度，分析环渤海地区单站寒潮和区域寒潮的气候变化特征。结果表明：环渤海地区单站寒潮出现频次的地域差异很大，大体上呈现自北至南递减态势，年平均次数最多的为张北21次，最少的京津地区不足2次。近50 a来环渤海地区共有233次区域性寒潮，出现在当年9月至次年4月，其中11月最多。区域寒潮呈显著减少趋势。20世纪60-70年代区域性寒潮事件频发，80年代开始明显减少并在1983年出现了突变。区域特强寒潮不多，20世纪60年代出现了2次，自70年开始特强寒潮平均每个年代出现1次。在气候变暖背景下，环渤海地区区域寒潮次数明显减少，但特强寒潮亦极端寒潮事件并未减少。

Temporal and spatial distribution of cold wave and its variation around the Bohai Sea region from 1961 to 2010

Based on the daily mean and minimum temperatures at 58 weather stations around the Bohai Sea region from 1961 to 2010,the frequency and intensity of cold wave were analyzed in terms of the national standard on cold wave, and the climatic characteristics of cold wave in a single station and in the whole study area were dis- cussed. The results indicate that the regional differences of cold wave frequencies in a single station are significant. In general,the cold wave is in a decreasing trend from north to south around the Bohai Sea region,and the number of annual mean cold wave is 21 in Zhangbei station and it is the highest among all stations,while the number is less than 2 in the stations of Beijing and Tianjin region. There are 233 regional cold waves in the recent 50 years and it appears mainly from September to April,especially in November,and it is in a significant decreasing trend. The frequencies of regional cold wave is the highest from 1960s to 1970s,while it decreases since 1980s and an abrupt change appears in 1983. The extreme strong regional cold wave is rare,and it is only twice in 1960s and once per ten years since 1970s. The regional cold wave decreases significantly under the global warming back- ground around the Bohai Sea region, while the extreme strong cold wave events do not decrease.